Plenary Lecture

The Paleontological History of Wildfire: An Important Tool to Define Fluctuations in the Atmospheric Composition

Professor André Jasper
Botanica, Paleobotanica e Evolucao de Biomas
PPG - Ambiente e Desenvolvimento
Centro de Ciencias Biologicas e da Saude
Museu de Ciencias Naturais
Setor de Botanica e Paleobotanica
Rua Avelino Tallini, 171
Bairro Universitario, Lajeado
Rio Grande do Sul, Brasil
E-mail: ajasper@univates.br
URL: http://www.univates.br

Abstract: The study of the actual biomes is more and more connected to the environmental processes occurred in its genesis. The actual stability, for the human conditions, is fragile and correlated with an important element: the composition of the atmosphere. In this way, we can observe the recent discussions about the global warming, correlate with the upgrade of the concentration of Carbon in the atmosphere. It is obvious that the human activities have a great influence in the global climatic changes. However, the study of the geological and paleontological registers, can confirm that these changes normally occurred in the Earth’s history. One of the most important forms of control of the atmosphere composition is the presence of the “Fire Window”, an interval of atmospheric oxygen level (13 to 35%) that permits the occurrence of wildfire. Moreover, if we accept that, over the geologic time, fluctuations in atmospheric gases levels have influenced biological evolution and had an integral role in the feedback mechanisms that governing Earth’s biogeochemical cycles, the study of the events is fundamental to establish models for the future. Thus, the evaluation of occurrence, frequency and conditions of palaeowildfires, through study of charcoal (Fig. 1 and 2), a proxy for fire, can contribute for the construction of models that enable a planning of future actions of environmental management.
	Figure 1: Scanning Electron Micrograph of a charcoal with gimnospermic affinity from the Early Permian of South America (scale bar = 40 μm).
	Figure 2: Scanning Electron Micrograph of a charcoal from the Early Permian of South America with the cellular walls indicating a fire of 230 – 340ºC (scale bar = 15 μm).
Brief Biography of the Speaker: Jasper is Biologist in its first degree formation and developed it Master and PhD degrees in Paleobotany at the Geosciences Institute of the Federal University of Rio Grande do Sul (UFRGS), Brazil. Made the Postdoctoral stage at the Geosciences Institute of the University of Tübingen, Germany. His main areas of interest are Paleobotany, Evolution of Terrestrial Biomes and Study of Paleowildfires. In addition he compares the Paleoecological data with the actual situation of the environments to be able to determine differences between the planetary events with natural origin and those caused by human action. Actually he works at the Museum of Natural Sciences of the UNIVATES, Brazil, and is Titular Professor for Paleontology in the same University. He is also Guest Professor at the UNICAMP, Brazil, and at the Halmstad University, Sweden.